Conventionally, there is disclosed a diaper of open type provided with an absorber and side flaps each extending to the outside in a widthwise direction than the absorber, in which a main elastic member is disposed to the outside in a product widthwise direction than the absorber, and a subsidiary elastic member is disposed at the outside in the product widthwise direction than the main elastic member (refer to FIG. 1, FIG. 2, and page 4 to page 5 of Patent Literature 1).
The main elastic member is disposed around a wearer's leg-hole. The subsidiary elastic member is disposed to the outside in the product widthwise direction than the main elastic member in the vicinity of an end of a longitudinal direction of a disposable diaper. The end of the product widthwise direction of the diaper is shrunk by the subsidiary elastic member, and a side leakage of urine or the like can be prevented.